Nowadays, with the popularization of the digital products, more and more users shoot the videos through Digital Videos (DV) or cameras with the video function. But the media file created in this way has an obvious disadvantage that the file usually has a large size and occupies a bulky disk space. For example, the file obtained by shooting with the common DV for one hour may be 2 G or more. Thus for the user's convenience of storing such large video file, a utility tool is required to help the user to compress the file while maintaining the subjective quality of the video.
During the creation of the media file, the most critical operation is the audio and video (AV) encoding. There are various AV encoding standards to meet different business demands. For example, the H.263 standard for video telephone and video conference, the Moving Picture Experts Group2 (MPEG2) standard for Digital Video Broadcasting (DVB), high definition television (HDTV) and Digital Video Disc (DVD), the MPEG4 standard for the stream media service in the network, and the H.264 standard that provides a high video compression performance.
Due to the existence of various encoding standards, the media files owned by the user have different file formats and AV encoding formats. In order to compress a file, a file parse and an AV decoding shall be carried out firstly; and after the original AV streams are obtained, appropriate AV transcoders and transcoding parameters shall be selected to create a new media file with a smaller size. Thus when a media file is to be compressed, the format information of the media file shall be analyzed at first, and then the transcoding parameters shall be determined according the efficiency of the encoder and the encoding parameters used for the source file. The current video compression tool usually requires the user to understand the media expertise deeply and set appropriate transcoding parameters, so as to achieve a good compression effect. However, for an ordinary and popular user, it is difficult to use such kind of video compression tool, thus a simple and rapid compression method and utility tool are required to meet the compression demand.